what was "the chat problem" ?
Online gaming where the only communication between players is jumping and canned voice lines is a wildly different experience.
It's actually probably the same problem drivers face. When driving, your brain kind of ignores that other normal humans drive the other cars, and therefore you are extremely judgemental of their actions, because you expect them to be perfect. This is why so many people road rage.
It's generally the ones that have children in them that get toxic - I would guess because children have less developed social filters and act out their negative emotions more readily than adults.
That is the problem. Kids are learning from each other to be harmful and hateful as there is no consequences for that behaviour. In other spaces they will be called out by adults, but game chats become a learning place for the worst behaviours at the same time that this games are rated as "apt for children". Rate them 18+ or kill the chat, it is all about not lying to buyers.